The present invention relates to a system and method for teaching and training students in medical procedures, and in particular to a system and method for training students in the procedure of endoscopy for urology.
Endoscopy is an example of a minimally invasive medical procedure, which can be performed on a number of different organ systems, such as the gastrointestinal tract and the urethra. Flexible gastro-endoscopy is an important medical tool for both surgical and diagnostic procedures in the urological organ system. Essentially, gastro-endoscopy is performed by inserting an endoscope, which is a flexible tube, into the gastrointestinal system, either through the mouth or the rectum of the subject. The tube is manipulated by a trained physician through specialized controls. The end of the tube which is inserted into the subject contains a camera and one or more surgical tools, such as a clipper for removing tissue samples from the gastrointestinal system. The physician must maneuver the tube according to images of the gastrointestinal system received from the camera and displayed on a video screen. The lack of direct visual feedback from the gastrointestinal system is one factor which renders endoscopy a complex and difficult procedure to master. Such lack of feedback also increases the difficulty of hand-eye coordination and correct manipulation of the endoscopic device. Thus, flexible gastro-endoscopy is a difficult procedure to both perform and to learn.
Currently, students are taught to perform flexible gastro-endoscopy according to the traditional model for medical education, in which students observe and assist more experienced physicians. Unfortunately, such observation alone cannot provide the necessary training for such complicated medical procedures. Students may also perform procedures on animals and human cadavers, neither of which replicates the visual and tactile sensations of a live human patient. Thus, traditional medical training is not adequate for modern technologically complex medical procedures.
In an attempt to provide more realistic medical training for such procedures, simulation devices have been developed which attempt to replicate the tactile sensations and/or visual feedback for these procedures, in order to provide improved medical training without endangering human patients. An example of such a simulation device is disclosed in U.S. Pat. No. 5,403,191, in which the disclosed device is a box containing simulated human organs. Various surgical laparoscopic procedures can be performed on the simulated organs. Visual feedback is provided by a system of mirrors. However, the system of both visual and tactile feedback is primitive in this device, and does not provide a true representation of the visual and tactile sensations which would accompany such surgical procedures in a human patient. Furthermore, the box itself is not a realistic representation of the three-dimensional structure of a human patient. Thus, the disclosed device is lacking in many important aspects and fails to meet the needs of a medical simulation device.
Attempts to provide a more realistic experience from a medical simulation devices are disclosed in PCT Patent Application Nos. WO 96/16389 and WO 95/02233. Both of these applications disclose a device for providing a simulation of the surgical procedure of laparoscopy. Both devices include a mannequin in the shape of a human torso, with various points at which simulated surgical instruments are placed. However, the devices are limited in that the positions of the simulated surgical instruments are predetermined, which is not a realistic scenario. Furthermore, the visual feedback is based upon a stream of video images taken from actual surgical procedures. However, such simple rendering of video images would result in inaccurate or unrealistic images as portions of the video data would need to be removed for greater processing speed. Alternatively, the video processing would consume such massive amounts of computational time and resources that the entire system would fail to respond in a realistic time period to the actions of the student. At the very minimum, a dedicated graphics workstation would be required, rather than a personal computer (PC). Thus, neither reference teaches or discloses adequate visual processing for real time visual feedback of the simulated medical procedure.
Similarly, U.S. Pat. No. 4,907,973 discloses a device for simulating the medical procedure of flexible gastro-endoscopy. The disclosed device also suffers from the deficiencies of the above-referenced prior art devices, in that the visual feedback system is based upon rendering of video data taken from actual endoscopic procedures. As noted previously, displaying such data would either require massive computational resources, or else would simply require too much time for a realistic visual feedback response. Thus, the disclosed device also suffers from the deficiencies of the prior art.
A more useful and efficient medical simulation device for minimally invasive therapeutic procedures such as endoscopy is disclosed in PCT Application No. WO 99/38141. The disclosed medical simulation device provides real time, accurate and realistic visual feedback of general endoscopic procedures, as well as realistic tactile feedback, so that the visual and tactile systems are accurately linked for the simulation as for an actual medical procedure.
Another type of endoscopic procedure, for urology, would also benefit from such realistic simulation, involving both visual and tactile feedback which are provided in an accurate manner. Urological endoscopic procedures feature many of the same principles as gastro-endoscopy, since for both types of endoscopic procedures, an instrument is inserted into a body orifice, and must then be guided through a tubular organ without direct visual feedback. In addition, the physician performing the procedure must be able to correctly interpret both the indirect visual feedback provided through a video monitor, as well as the tactile feedback through the instrument itself. Therefore, both types of endoscopy require the physician to receive “hands-on” manual training for the correct performance of the procedure.
In addition, urological endoscopy has other features which differ from gastro-endoscopy. For example, before the endoscope can be introduced into the ureteral opening, a guidewire must be inserted into the ureter and moved up to the kidney. If the guidewire is inserted too quickly and/or with too much force, the tip of the guidewire may penetrate the bladder wall or even the kidney. Therefore, the operation of the guidewire as well as of the endoscope itself must be modeled. Also, the endoscope may be maneuvered through one of three paths for urological endoscopy, as opposed to a single path for gastro-endoscopy: one path for each kidney, and a third path through the urethra to the top of the bladder. Furthermore, along this path the ureter crosses the illiac vessel such that the ureter in that area actually moves according to the rate of the beating heart. Such movement must also be modeled for an accurate simulation of the urological procedure. Finally, urological endoscopy may also involve the optional procedure of contrast dye injection into the urological system. Thus, although urological endoscopy shares many features with gastro-endoscopy, the former procedure must be separately simulated for accurate training and simulation.
There is therefore a need for, and it would be useful to have, a method and a system to simulate urological endoscopy, which would provide accurate, linked visual and tactile feedback to the student and which would serve as a training resource for all aspects of the procedure.